Eddy current separator

Abstract

An eddy current separator (“ECS”) separates electroconductive and non-electroconductive materials. The materials can include “fines” having diameters less than about 10 millimeters. The ECS includes first and second hubs coupled to opposite ends of a magnet support tube. Magnets are coupled to the magnet support tube, substantially between the hubs. A motor coupled to one or both of the hubs rotates the magnet support tube and magnets to generate an eddy current in electroconductive material conveyed proximate the separator. The material in which the eddy current is created is repelled and projected away from the ECS along a predictable trajectory. An eddy current is not generated in nonconductive material conveyed proximate the separator. Therefore, that material is not projected away. A jacket tube may house the magnets and contain centrifugal forces of the magnets during rotation thereof That tube may comprise a Ti60 titanium alloy or other material.

What is claimed is: 
     
       1. A method for separating electroconductive materials from nonelectroconductive materials, the method comprising:
 conveying a material to a separator, the material including the electroconductive materials and the nonelectroconductive materials; 
 generating an eddy current at the separator using a motor coupled to a magnetic support tube, the magnetic support having a plurality of magnets coupled thereto and having a length of about 1.5 meters; 
 operating the motor at a frequency of at least about 4,000 rotations per minute 
 inducing the eddy current in the electroconductive materials to transport the electroconductive materials away from the separator; 
 collecting the electroconductive materials in a first receptacle; and 
 collecting the nonelectroconductive materials in a second receptacle. 
 
     
     
       2. The method of  claim 1 , further comprising:
 separating the material according to size before conveying the material to the separator. 
 
     
     
       3. The method of  claim 1 , further comprising:
 operating the motor at a frequency of at least about 6,000 rotations per minute; 
 wherein the magnetic support tube has a length of about one meter. 
 
     
     
       4. The method of  claim 1 , further comprising:
 operating the motor at a frequency of at least about 3,000 rotations per minute, and 
 wherein the magnetic support tube has a length of at least about 2.5 meters. 
 
     
     
       5. The method of  claim 4 , wherein the magnetic support tube has a length of at least about 3 meters. 
     
     
       6. The method of  claim 1 , wherein each of the electroconductive materials have a diameter less than about 10 millimeters. 
     
     
       7. A system for separating electroconductive materials from nonelectroconductive materials, comprising:
 a conveyor for providing a material to a separator, the material including the electroconductive materials and the nonelectroconductive materials; and 
 the separator including:
 a magnet support tube having a plurality of magnets coupled thereto; 
 a jacket tube housing the plurality of magnets, the jacket tube operable to contain the centrifugal forces of the plurality of magnets during rotation; 
 a first hub coupled to a first end of the magnet support tube; 
 a second hub coupled to a second end of the magnet support tube; and 
 a motor coupled to at least one of the first hub and the second hub, the motor rotating the magnet support tube and the plurality of magnets to generate an eddy current in the electroconductive materials conveyed proximate the separator and transport the electroconductive materials away from the separator. 
 
 
     
     
       8. The system of  claim 7 , wherein the jacket tube has a negative allowance. 
     
     
       9. The system of  claim 7 , wherein the jacket tube comprises a titanium alloy. 
     
     
       10. The system of  claim 7 , further comprising:
 a screen for segregating the material according to size. 
 
     
     
       11. The system of  claim 7 , wherein the magnet support tube has a natural frequency of about 28,000 rotations per minute. 
     
     
       12. The system of  claim 7 , wherein the plurality of magnets are arranged in a series of axial rows around the magnetic support tube. 
     
     
       13. The system of  claim 7 , wherein each of the plurality of magnets in a same axial row have a same polar orientation and each of the plurality of magnets in an adjacent axial row have an opposite polar orientation. 
     
     
       14. The system of  claim 7 , wherein the motor operates at a frequency of at least about 6,000 rotations per minute; and
 wherein the magnetic support tube has a length of about one meter. 
 
     
     
       15. The system of  claim 7 , wherein the motor operates at a frequency of at least about 4,000 rotations per minute, and
 wherein the magnetic support tube has a length of about 1.5 meters. 
 
     
     
       16. The system of  claim 7 , wherein the motor operates at a frequency of at least about 3,000 rotations per minute, and
 wherein the magnetic support tube has a length of at least about 2.5 meters. 
 
     
     
       17. The system of  claim 7 , wherein the electroconductive materials have a diameter less than about 10 millimeters. 
     
     
       18. The system of  claim 7 , further comprising:
 a first receptacle for collecting the electroconductive materials, and 
 a second receptacle for collecting the nonelectroconductive materials. 
 
     
     
       19. A method for separating electroconductive materials from nonelectroconductive materials, the method comprising:
 conveying a material to a separator, the material including the electroconductive materials and the nonelectroconductive materials; 
 generating an eddy current at the separator using a motor coupled to a magnetic support tube, the magnetic support having a plurality of magnets coupled thereto and having a length of about 2.5 meters; 
 operating the motor at a frequency of at least about 3,000 rotations per minute 
 inducing the eddy current in the electroconductive materials to transport the electroconductive materials away from the separator; 
 collecting the electroconductive materials in a first receptacle; and 
 collecting the nonelectroconductive materials in a second receptacle. 
 
     
     
       20. The method of  claim 19 , wherein the magnetic support tube has a length of at least about 3 meters.